// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE-BSD file. See the AUTHORS file for names of contributors.

// SPDX-License-Identifier: Apache-2.0
/* Copyright 2020, Intel Corporation */

#include "util/logging.h"

#include "leveldb/env.h"
#include "leveldb/slice.h"
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>

namespace leveldb
{

void AppendNumberTo(std::string *str, uint64_t num)
{
	char buf[30];
	snprintf(buf, sizeof(buf), "%llu", (unsigned long long)num);
	str->append(buf);
}

void AppendEscapedStringTo(std::string *str, const Slice &value)
{
	for (size_t i = 0; i < value.size(); i++) {
		char c = value[i];
		if (c >= ' ' && c <= '~') {
			str->push_back(c);
		} else {
			char buf[10];
			snprintf(buf, sizeof(buf), "\\x%02x", static_cast<unsigned int>(c) & 0xff);
			str->append(buf);
		}
	}
}

std::string NumberToString(uint64_t num)
{
	std::string r;
	AppendNumberTo(&r, num);
	return r;
}

std::string EscapeString(const Slice &value)
{
	std::string r;
	AppendEscapedStringTo(&r, value);
	return r;
}

bool ConsumeDecimalNumber(Slice *in, uint64_t *val)
{
	uint64_t v = 0;
	int digits = 0;
	while (!in->empty()) {
		char c = (*in)[0];
		if (c >= '0' && c <= '9') {
			++digits;
			// |delta| intentionally unit64_t to avoid Android crash (see log).
			const uint64_t delta = (c - '0');
			static const uint64_t kMaxUint64 = ~static_cast<uint64_t>(0);
			if (v > kMaxUint64 / 10 || (v == kMaxUint64 / 10 && delta > kMaxUint64 % 10)) {
				// Overflow
				return false;
			}
			v = (v * 10) + delta;
			in->remove_prefix(1);
		} else {
			break;
		}
	}
	*val = v;
	return (digits > 0);
}

} // namespace leveldb
